52
52
audio
eye 52
favorite 0
comment 0
We take a look at some common writing mistakes and how to fix them.
Topics: writing mistakes, helium, writer, writing, write, freelance, freelancing, freelance writer, become...
11
11
audio
eye 11
favorite 0
comment 0
Topics: Radio Program, Learning, Association football midfielders, Atoms, Broadcasting, Broadcast...
Topics: Radio Program, Physical cosmology, Astroparticle physics, Black Hills, NPR programs, Psychotherapy,...
Topics: Radio Program, American physicists, Physical cosmology, Theoretical physicists, Universe, Coolants,...
For three decades, magnetospheric field and plasma measurements have been made by diverse instruments flown on spacecraft in may different orbits, widely separated in space and time, and under various solar and magnetospheric conditions. Scientists have used this information to piece together an intricate, yet incomplete view of the magnetosphere. A simultaneous global view, using various light wavelengths and energetic neutral atoms, could reveal exciting new data nd help explain complex...
Topics: NASA Technical Reports Server (NTRS), EARTH MAGNETOSPHERE, EARTH OBSERVATIONS (FROM SPACE), IMAGING...
The objective of the present research program is to develop a comprehensive, predictive, and detailed kinetic model of hydrocarbon combustion for aeropropulsion simulations. During the reporting period progress has been made in the following projects: (1) a comparative study of the influence of reaction rate constant and binary diffusion coefficient on laminar flame speed predictions and close coupled scattering calculations for the binary diffusion coefficients of H-He and H-Ar, (2) a study on...
Topics: DTIC Archive, Wang, Hai, DELAWARE UNIV NEWARK DEPT OF MECHANICAL ENGINEERING, *MATHEMATICAL MODELS,...
An exploratory study was performed on a jet-flapped airfoil in the Low Speed Flow Visualization Facility at the Naval Postgraduate School, Monterey, California. the purpose of this study was to evaluate the test facility for future work and to compare an old and a relatively new flow visualization technique. thee techniques are smoke flow and helium bubble flow. The study was conducted using various tunnel speeds and blowing rates of the jet flap. The varying of these parameters and the...
Topics: Aeronautics, Flow visualization, Helium bubble flow, Jet flap, Smoke flow
Memory tubes were devised to sample the gas composition in the Space Shuttle Main Engine (SSME) duct at many locations (33-100) using only a few mass spectrometers. The feasibility of this technique was evaluated by examining the capability of long tubes to transport and store time-varying gas composition data with sufficient time resolution to rule out the existence of hazardous hydrogen-air mixtures in the duct. The procedure was 1) to examine the theoretical and experimental behavior of gas...
Topics: DTIC Archive, Hertz, Robert A, AEROSPACE CORP EL SEGUNDO CA AEROPHYSICS LAB, *TUBES, *SPACE...
An experimental program was carried out in the 10 to the -8 to 10 to the -2 power torr region to supply basic information on the adsorption of noncondensable gases at 77 K and to establish the functional dependence of adsorption rate on pressure and amount of gas adsorbed. From the experimental results, analytical expressions are developed which describe the behavior of adsorption rate in terms of the adsorption parameters for high vacuum, low temperature conditions. These expressions are shown...
Topics: DTIC Archive, Kindall, S M, ARO INC ARNOLD AFS TN, *CHARCOAL, ADSORPTION, ARGON, EQUATIONS OF...
Crossed electric and magnetic fields are used to focus a beam of charged particles and to control the drift velocity of these particles. The novel and useful properties are: (1) the time delay can be varied continuously and rapidly; (2) the frequency band is potentially very wide. A discussion of the effects that limit bandwidth is presented and several means for reducing the limitations are described. In particular, a hyperboloidal structure is described that can maintain equal flight times in...
Topics: DTIC Archive, ILLINOIS UNIV AT URBANA COORDINATED SCIENCE LAB, *CROSSED FIELD DEVICES, *DELAY...
Determinations are given for diagrams of p - x - mixtures of helium- nitrogen under pressure of 5 to 150 atm and at temperatures of 64, 78, 90 and 108K and diagrams of T-x at 4 and 20 atm. Calculations are given for i- xdiagrams for pressures of 4 and 20 atm on the basis of T-x-diagrams. The purpose of the study was to solve the problem of obtaining pure helium from natural gases with the least possible losses of helium.
Topics: DTIC Archive, REDSTONE SCIENTIFIC INFORMATION CENTER REDSTONE ARSENAL AL, *NITROGEN, *HELIUM, PHASE...
The calibration of the Hertzsprung-Russell diagram in terms of age and mass for main-sequence B and A stars presented in this paper was derived from the results of the Kelsall evolutionary model sequence calculations.
Topics: DTIC Archive, Kelsall, T, INSTITUTE FOR ADVANCED STUDY PRINCETON NJ, *STARS, LIFE...
An experimental study of the forced convection heat loss from long thin cylinders placed normal to an incompressible flow was carried out. Tests were made in three different gases (air, argon, helium) at atmospheric pressure and in air over a pressure range 0.2 to 8 atm. Particular attention was given to determining the effect of cylinder temperature on the heat loss. It was found that the constants employed in the usual empirical representation of this heat loss vary with cylinder temperature...
Topics: DTIC Archive, WEBB, W H, PRINCETON UNIV NJ JAMES FORRESTAL RESEARCH CENTER, *ANEMOMETERS,...
Over the past few years RWME has been investigating the use of the liquid helium droplet beam technique to generate of single component and composite nanoclusters at low temperature, deposit the clusters onto various substrates, and then investigate the stability, chemical, and physical properties of the subsequent cluster-based material. This report provides an annual status update in the understanding of the environment of the clusters prior to, during, and after collision of the doped...
Topics: DTIC Archive, Ridge,Claron J, Munitions Directorate Eglin AFB United States, energetic materials,...
Temperature variations of the quasi-diffusion constant and thermal diffusion ratio between phonon and roton gases in two and three-dimensional liquid helium are evaluated explicitly through the scattering of phonons by rotons. The diffusion constants in both dimensions decrease exponentially over the whole temperature range, while the thermal diffusion ratios increase and then decrease as temperature increases in the range from about 0.6 to about 1.1 K.
Topics: DTIC Archive, Um, C I, STATE UNIV OF NEW YORK AT BUFFALO DEPT OF CHEMISTRY, *LIQUID HELIUM,...
The physiological research performed under the Contract ranged from cellular function and membrane function to the performance of whole organisms under conditions relevant to the diver's situation. A study of ionic currents in the voltage-clamped squid axon exposed to helium pressures of up to 204 atmospheres has been performed. One study addressed the effects of pressure perse on sodium transport and ATPase activity in human erythrocytes. A major area of research initiated under this Contract...
Topics: DTIC Archive, Rahn,H, STATE UNIV OF NEW YORK AT BUFFALO DEPT OF PHYSIOLOGY, *REHABILITATION,...
1
1.0
Jun 11, 2021
06/21
by
Matt Spaustat (Undreamt3D)
data
eye 1
favorite 0
comment 0
I laser cut a new top for my RAK miner since I was using wifi and heard many were taking the tops off of theirs to improve the wifi signal. I've got little kiddos so I figured this would be more safe. Here's how it turned out and attached the DXF file for others to use and cut if they desire. I used 3mm Acrylic
Topics: Helium, Miner, stl, thingiverse, DIY, RAK
This thesis describes the development of PdMn thin films for high resolution thermometry. Measurements of the magnetic sensitivity of sputtered thin films of PdMn alloy suggest that the sputtering technique produces an ordered film with a manganese concentration slightly higher than the nominal value of the sputtering target. Sputtering from a 0.68% manganese target produced films with a concentration of approximately 0.90%, as judged by comparison with results from bulk PdMn sensitivity...
Topics: DTIC Archive, Nelson, Raymond C, NEW MEXICO UNIV ALBUQUERQUE DEPT OF PHYSICS AND ASTRONOMY, *THIN...
The development of a Dewar system for handling liquid helium under weightless conditions is described. Porous plug designs for the prevention of superfluid creep out of the dewar through the vent line were evaluated. For the purpose of designing a neck to provide a transition from the cold cavity to the outside, the loads carried by the neck and equipment supports were studied. Temperature, pressure, and mass flow instrumentation for monitoring Dewar performance were also evaluated. In...
Topics: NASA Technical Reports Server (NTRS), CRYOGENIC EQUIPMENT, LIQUID HELIUM, SUPERFLUIDITY, FLOW...
The application of refrigeration at low temperatures ranging from production of liquid helium for medical imaging systems to cooling of infrared sensors on surveillance satellites is discussed. Cooling below about 15 K with regenerative refrigerators is difficult because of the decreasing thermal mass of the regenerator compared to that of the working material. In order to overcome this difficulty with helium gas as the working material, a heat exchanger plus a Joule-Thomson or other exponder...
Topics: NASA Technical Reports Server (NTRS), CARNOT CYCLE, CRYOGENIC COOLING, INFRARED DETECTORS, LIQUID...
In this effort, a new design concept for an adiabatic demagnetization refrigerator (ADR) that is capable of operation in zero gravity has been developed. The design uses a vortex precooler to lower the initial temperature of magnetic salt from the initial space superfluid helium dewar of 1.8 K to 1.1 K. This reduces the required maximum magnetic field from 4 Tesla to 2 Tesla. The laboratory prototype vortex precooler reached a minimum temperature of 0.78 K, and had a cooling power of 1 mW at...
Topics: NASA Technical Reports Server (NTRS), ADIABATIC CONDITIONS, CRYOGENIC EQUIPMENT, DEMAGNETIZATION,...
Method of producing porous copper plugs combines hydrogen annealing and oxygen annealing. Plugs have high thermal conductivity and small pore size.
Topics: NASA Technical Reports Server (NTRS), ANNEALING, COPPER, CRYOGENIC EQUIPMENT, FABRICATION, LIQUID...
Topics: Radio Program, Physical cosmology, Astroparticle physics, Psychotherapy, Universe, International...
56
56
Jun 30, 2010
06/10
by
London, Fritz, 1900-1954
texts
eye 56
favorite 0
comment 0
Bibliographical footnotes. Bibliography: v. 2, p. 206
Topics: Electric conductivity, Fluids, Helium, Superfluidité, Superconductivité
Panorama Vol 10 No 02 1971
Topics: magnetic, tho, object, ufo, ufos, venus, image, waves, light, appeared, magnetic field, gravity...
A new 20 K helium refrigerator installed at NASA Johnson Space Center's Space Environment Simulation Laboratory (SESL) was successfully commissioned and tested in 2012. The refrigerator is used to create a deep space environment within SESL s Chamber A to perform ground testing of the James Webb Space Telescope. The chamber previously and currently still has helium cryopumping panels (CPP) and LN2 shrouds used to create Low Earth Orbit environments. Now with the new refrigerator and new helium...
Topics: NASA Technical Reports Server (NTRS), AEROSPACE ENVIRONMENTS, REFRIGERATORS, JAMES WEBB SPACE...
0
0.0
Nov 8, 2021
11/21
by
Ian Clendaniel (clendaniel)
data
eye 0
favorite 0
comment 0
Two lids for use with the original modular case system to allow Rak2287 and Rak2245 Pi hats/concentrators exposing the heatsink for cooling (and hotrod looks) as well as adding a boss with hex for an external SMA connector. Useful for those that have legacy alpha DIY miners, building data-only hotspots or those looking to modify/upgrade third party miners where changing the case will be necessary.
Topics: LoRaWAN, stl, Computer, Helium_Miner, LoRa, thingiverse, HNT, Helium
1
1.0
Apr 4, 2021
04/21
by
Adrián Montero (adrititus)
data
eye 1
favorite 0
comment 0
Hola! Este es un soporte de Reelsteady para la GoPro Session 5 para el frame Helium. Sobresale un poco por los laterales, ya se irá ajustando. Buen Vuelo!
Topics: thingiverse, R/C Vehicles, dedrones_helium, dedrones_reddy, stl, dedrones
1
1.0
Apr 4, 2021
04/21
by
Adrián Montero (adrititus)
data
eye 1
favorite 0
comment 0
Hola! Esta es una pieza para proteger un poco más las patas del Helium de golpes. Es una versión modificada de: https://www.thingiverse.com/thing:3888683 Buenos vuelos!
Topics: thingiverse, R/C Vehicles, dedrones_helium, dedrones_reddy, stl, dedrones
http://uf.catalog.fcla.edu/uf.jsp?st=UF002726140&ix=pm&I=0&V=D&pm=1
Topics: Glow discharges, Argon, Helium, Mass spectrometry.
28
28
Feb 25, 2014
02/14
by
London, Fritz, 1900-1954
texts
eye 28
favorite 1
comment 0
"List of publications of Fritz London [prepared by Edith London]": v. 1, p. xv-xviii
Topics: Electric conductivity, Fluids, Helium
It has long been recognized that solar wind bombardment onto exposed surfaces in the solar system will produce an energetic component to the exospheres about those bodies. Laboratory experiments have shown that there is no increase in the sputtering yield caused by highly charged heavy ions for metallic and for semiconducting surfaces, but the sputter yield can be noticeably increased in the case of a good insulating surface. Recently measurements of the solar wind composition have become...
Topics: NASA Technical Reports Server (NTRS), ENERGETIC PARTICLES, SOLAR WIND, SPUTTERING, SOLAR PLANETARY...
An apparatus for determining helium to hydrogen ratios in a gaseous sample is presented. The sample is bombarded with alpha particles created by a self contained radioactive source and scattering products falling within a predetermined forward scattering angular range impact a detector assembly. Two detectors are mounted in tandem, the first completely blocking the second with respect to incident scattering products. Alpha particle/hydrogen or alpha particle/helium collisions are identified by...
Topics: NASA Technical Reports Server (NTRS), ALPHA PARTICLES, GAS COMPOSITION, HELIUM HYDROGEN...
237
237
Jul 12, 2010
07/10
by
NON
texts
eye 237
favorite 0
comment 0
No Abstract Available
Topics: ENGINE TESTS, PROTOTYPES, STIRLING CYCLE, AUTOMOBILE ENGINES, HELIUM
It is well known that solar-wind-implanted hydrogen and helium-3 in lunar soils are potentially usable resources for future manned activities. For economical mining of these implanted gases, it is desirable that relative concentrations exceed that of typical soils. It has previously been noted that the monthly variation of solar wind flux on the surface due to lunar immersion in the geomagnetic tail may have measurable consequences for resource utilization. It is pointed out that, for a...
Topics: NASA Technical Reports Server (NTRS), HELIUM ISOTOPES, LUNAR COMPOSITION, LUNAR MAGNETIC FIELDS,...
The Saturn system presents exciting and unique objects for planetary aeronomy. The photochemistry of H2 and He leads to the formation of an ionosphere. Methane photolysis results in the formation of spectroscopically detectable amounts of C2H6 and C2H2 and in the case of Titan, C2H4. Density profiles of C2H6, C2H2, and PH3 should be indicative of the strength of atmospheric mixing processes.
Topics: NASA Technical Reports Server (NTRS), ATMOSPHERIC COMPOSITION, PHOTOCHEMICAL REACTIONS, SATURN...
Topics: Radio Program, Law enforcement, Single-party states, Police ranks in the United Kingdom, Police...
Typescript
Topics: Low temperatures, Superfluidity, Liquid helium, Magnetohydrodynamics
61
61
texts
eye 61
favorite 0
comment 0
Topic: Helium -- Bibliography.
27
27
Feb 18, 2016
02/16
by
Florian Freistetter
audio
eye 27
favorite 0
comment 0
So gut wie alle Energie die wir nutzen kommt von der Sonne. Aber wie kriegt die Sonne das eigentlich hin? Was stellt sie an, um diese großen Mengen an Energie zu produzieren? Klar, dort findet Kernfusion statt. Wasserstoff wird zu Helium. Aber wenn man die Sache genau betrachtet, ist es schon ein klein wenig komplizierter. Wie unser Stern aus Materie Energie macht und damit unsere Lebensgrundlage sichert, ist das Thema der aktuellen Folge der Sternengeschichten.
Topics: Universum, Sternengeschichten, Astrodicticum, Sterne, Planeten, Astronomie, Sonne, Fusion,...
9
9.0
audio
eye 9
favorite 0
comment 0
Topics: Radio Program, Planetary science, Space plasmas, American bloggers, NASA space probes, Social...
Click here to view the University of Florida catalog record
Topics: Solid helium, Low temperature research
The microwave arcjet thruster uses microwave energy to create a free-floating plasma discharge within a microwave resonant cavity. This discharge typically absorbs 99% of the input power and converts it to thermal energy which is then transferred to the flowing propellant gas. Recent modifications have allowed the thruster to be operated in a fixed configuration where neither the cavity geometry nor the tuning mechanisms are adjusted. The prototype has demonstrated its ability to operate in...
Topics: NASA Technical Reports Server (NTRS), ARC JET ENGINES, ELECTRIC ROCKET ENGINES, ENGINE DESIGN, GAS...
10
10.0
audio
eye 10
favorite 0
comment 0
Topics: Radio Program, Heads of government, Abuse, Criminology, Single-party states, Punishments, Political...
8
8.0
audio
eye 8
favorite 0
comment 0
Topics: Radio Program, Radioactivity, Dairy products, Refrigerants, Nuclear physics, Coolants, Divided...
Topics: Radio Program, Planetary science, Space plasmas, Social psychology, American businesspeople, Sun,...
8
8.0
audio
eye 8
favorite 0
comment 0
Topics: Radio Program, Learning, Association football midfielders, Atoms, Mass media, Broadcast...
A miniature mass spectrometer that incorporates features not typically found in prior mass spectrometers is undergoing development. This mass spectrometer is designed to simultaneously measure the relative concentrations of five gases (H2, He, N2, O2, and Ar) in air, over the relative-concentration range from 10(exp -6) to 1, during a sampling time as short as 1 second. It is intended to serve as a prototype of a product line of easy-to-use, portable, lightweight, highspeed, relatively...
Topics: NASA Technical Reports Server (NTRS), HYDROGEN, HELIUM, NITROGEN, OXYGEN, ARGON, MASS...
Topics: Radio Program, BBC World Service, Heads of government, Political science, Abuse, Criminology,...
Topics: Radio Program, Planetary science, Space plasmas, Social psychology, American businesspeople, Sun,...
